diff options
| -rw-r--r-- | arch/ia64/kvm/kvm-ia64.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 16 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 22 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 7 |
4 files changed, 35 insertions, 12 deletions
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 70d224d4264..8213efe1998 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -662,6 +662,7 @@ again: goto vcpu_run_fail; srcu_read_unlock(&vcpu->kvm->srcu, idx); + vcpu->mode = IN_GUEST_MODE; kvm_guest_enter(); /* @@ -683,6 +684,7 @@ again: */ barrier(); kvm_guest_exit(); + vcpu->mode = OUTSIDE_GUEST_MODE; preempt_enable(); idx = srcu_read_lock(&vcpu->kvm->srcu); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5eccdba08bd..a7f65aa6eef 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5210,14 +5210,18 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_load_guest_fpu(vcpu); kvm_load_guest_xcr0(vcpu); - atomic_set(&vcpu->guest_mode, 1); - smp_wmb(); + vcpu->mode = IN_GUEST_MODE; + + /* We should set ->mode before check ->requests, + * see the comment in make_all_cpus_request. + */ + smp_mb(); local_irq_disable(); - if (!atomic_read(&vcpu->guest_mode) || vcpu->requests + if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests || need_resched() || signal_pending(current)) { - atomic_set(&vcpu->guest_mode, 0); + vcpu->mode = OUTSIDE_GUEST_MODE; smp_wmb(); local_irq_enable(); preempt_enable(); @@ -5253,7 +5257,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_get_msr(vcpu, MSR_IA32_TSC, &vcpu->arch.last_guest_tsc); - atomic_set(&vcpu->guest_mode, 0); + vcpu->mode = OUTSIDE_GUEST_MODE; smp_wmb(); local_irq_enable(); @@ -6157,7 +6161,7 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) me = get_cpu(); if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) - if (atomic_xchg(&vcpu->guest_mode, 0)) + if (kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE) smp_send_reschedule(cpu); put_cpu(); } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b5021db2185..b99eacd988a 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -98,19 +98,26 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn, int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu); #endif +enum { + OUTSIDE_GUEST_MODE, + IN_GUEST_MODE, + EXITING_GUEST_MODE +}; + struct kvm_vcpu { struct kvm *kvm; #ifdef CONFIG_PREEMPT_NOTIFIERS struct preempt_notifier preempt_notifier; #endif + int cpu; int vcpu_id; - struct mutex mutex; - int cpu; - atomic_t guest_mode; - struct kvm_run *run; + int srcu_idx; + int mode; unsigned long requests; unsigned long guest_debug; - int srcu_idx; + + struct mutex mutex; + struct kvm_run *run; int fpu_active; int guest_fpu_loaded, guest_xcr0_loaded; @@ -140,6 +147,11 @@ struct kvm_vcpu { struct kvm_vcpu_arch arch; }; +static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu) +{ + return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE); +} + /* * Some of the bitops functions do not support too long bitmaps. * This number must be determined not to exceed such limits. diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fd67bcde998..19209f849cf 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -171,7 +171,12 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req) if (kvm_make_check_request(req, vcpu)) continue; cpu = vcpu->cpu; - if (cpus != NULL && cpu != -1 && cpu != me) + + /* Set ->requests bit before we read ->mode */ + smp_mb(); + + if (cpus != NULL && cpu != -1 && cpu != me && + kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE) cpumask_set_cpu(cpu, cpus); } if (unlikely(cpus == NULL)) |